4th National Climate Change Assessment Published

Prepared by the US Global Change Research Program, The National Climate Assessment (NCA) assesses the science of climate change and variability and its impacts across the United States, now and throughout this century.

On Water:
“Rising air and water temperatures and changes in precipitation are intensifying droughts, increasing heavy downpours, reducing snowpack, and causing declines in surface water quality, with varying impacts across regions. Future warming will add to the stress on water supplies and adversely impact the availability of water in parts of the United States. . . . Aging and deteriorating water infrastructure, typically designed for past environmental conditions, compounds the climate risk faced by society. Water management strategies that account for changing climate conditions can help reduce present and future risks to water security, but implementation of such practices remains limited.”
On Infrastructure:
“Our Nation’s aging and deteriorating infrastructure is further stressed by increases in heavy precipitation events, coastal flooding, heat, wildfires, and other extreme events, as well as changes to average precipitation and temperature. Without adaptation, climate change will continue to degrade infrastructure performance over the rest of the century, with the potential for cascading impacts that threaten our economy, national security, essential services, and health and well-being.”

“Across the Nation, much of the critical water infrastructure is aging and, in some cases, deteriorating or nearing the end of its design life, presenting an increased risk of failure . Estimated reconstruction and maintenance costs aggregated across dams, levees, aqueducts, sewers, and water and wastewater treatment systems total in the trillions of dollars based on a variety of different sources. Capital improvement needs for public water systems (which provide safe drinking water) have been estimated at $384 billion for projects necessary from 2011 through 2030. Similarly, capital investment needs for publicly owned wastewater conveyance and treatment facilities, combined sewer overflow correction, and storm water management to address water quality or water quality-related public health problems have been estimated at $271 billion over a 20-year period. More than 15,000 dams in the United States are listed as high risk due to the potential losses that may result if they failed.”